1. Field of the Invention
This invention relates to human body composition and, more particularly, to a system for measuring a user's body fat percentage taking into consideration hydration levels.
2. Background Art
Individuals and businesses worldwide are becoming increasingly interested in maintaining human health. From a business perspective, healthy employees are generally more productive and reliable. Preventable illnesses that result in employee down time are placing a greater strain on productivity requirements and the healthcare obligations of businesses for their employees. This problem is in addition to that of “covering” for employees during short or extended absences.
From an individual standpoint, good health contributes not only to longevity, but a more productive and enjoyable life.
With the increasing emphasis on health maintenance, technology has been evolving that allows individuals to more effectively monitor critical health parameters, among which is body fat percentage, a key indicator of overall health level. A multitude of instruments have been devised based upon bioimpedance technology, which relies upon the ability to measure resistance to a low level electrical signal introduced into the body at one location and received at another.
The assignee herein has developed a line of technology including bioimpedance instrumentation wherein an electrical signal is introduced through the user's one hand and received through the user's other hand. Exemplary technology is shown in applicant's pending application Ser. No. 10/882,139 entitled “Method and System for Evaluating A Cost For Health Care Coverage For An Entity”, the disclosure of which is incorporated herein by reference.
Generally, resistance is measured in ohms, with the applicant's commercial products having an ohms bridge allowing from 100-1100 ohms. The higher the ohms, the higher is the resistance. An ohms reading is then incorporated into an individual profile including age, weight, gender, height, and athletic activity. A person may be categorized and measurements derived therefor based upon whether the person is, for example, sedentary, inactive, active, athletic, a professional athlete, a bodybuilder, etc.
The low level electrical signals in this type of instrumentation pass through the body through any conductive material. In the human body, the most conductive route is water, that is contained within lean muscle, bone marrow, blood, main organs such as the bladder, etc. Water is not contained within fat.
Resistance measurement in the human body will also be affected by the level of hydration. If a user is underhydrated, the ohms reading/resistance will be higher. When this resistance value is processed through a bioimpedance device, the calculated body fat percentage will be artificially elevated, potentially as much as five percent or higher.
As this technology evolves, it is becoming more and more important that, for any meaningful reliance on calculated body fat percentage values, the accuracy be maintained so that there is a limited percentage error. The failure to take into account underhydration or dehydration may result in body fat percentage measurements that are significantly inaccurate and that may vary from one measurement to the next based upon fluctuation in hydration for the user.
The industry continues to seek out instrumentation that is affordable yet accurate to the point that health attributes can be accurately quantified and monitored to assist lifestyle selections that will improve and/or maintain users' overall health.